Conversion method and conversion apparatus

Abstract

A conversion method for converting luminance of a video, including a luminance value in a first luminance range, to be displayed on a display apparatus includes: acquiring a first luminance signal indicating a code value obtained by quantization of the luminance value of the video; and converting the code value indicated by the acquired first luminance signal into a second luminance value determined based on a luminance range of the display apparatus, the second luminance value being compatible with a second luminance range with a maximum value smaller than a maximum value of the first luminance range and larger than 100 nit. This provides the conversion method capable of achieving further improvement.

What is claimed is: 
     
       1. A display apparatus comprising: a display, storage; and processing circuitry that, in operation, performs operations including:
 performing electro-optical transfer function (EOTF) conversion for high dynamic range (HDR) on a video signal having a luminance range of HDR to generate a video linear signal; 
 converting a first graphics signal having a luminance range with a maximum luminance 100 nit into a second graphics signal having a luminance range with a maximum luminance value that is decided in accordance with a maximum luminance that is displayable by the display; 
 performing the EOTF conversion for HDR on the second graphics signal to generate a graphics linear signal; 
 combining the video linear signal with the graphics linear signal to generate a composite signal; 
 converting a luminance range of the composite signal into a luminance range having a maximum value, the maximum value being larger than 100 nit and being the maximum luminance that is displayable by the display; and wherein the display displays the composite signal with the luminance converted. 
 
     
     
       2. The display apparatus according to  claim 1 , wherein
 converting the first graphics signal having a luminance range with the maximum luminance 100 nit into the second graphics signal having the luminance range with a maximum luminance value that is decided in proportion to the maximum luminance that is displayable by the display. 
 
     
     
       3. A display apparatus comprising: a display, storage; and processing circuitry that, in operation, performs operations including:
 performing electro-optical transfer function (EOTF) conversion for high dynamic range (HDR) on a video signal having a luminance range with luminance range of HDR to generate a video linear signal; 
 performing the EOTF conversion for HDR on a graphics signal having a luminance range with a maximum luminance 100 nit to generate a first graphics linear signal; 
 converting the first graphics linear signal into a second graphics linear signal having a luminance range with a maximum luminance value that is decided in accordance with a maximum luminance that is displayable by a display; 
 combining the video linear signal with the second graphics linear signal to generate a composite signal; 
 converting a luminance range of the composite signal into a luminance range having a maximum value, the maximum value being larger than 100 nit and being the maximum luminance that is displayable by the display; and 
 and wherein the display displays the composite signal with the luminance converted. 
 
     
     
       4. The display apparatus according to  claim 3 , wherein
 converting the first graphics linear signal into the second graphics linear signal having the luminance range with a maximum luminance value that is decided in proportion to the maximum luminance that is displayable by the display. 
 
     
     
       5. The display apparatus according to  claim 1 , wherein
 the graphics signal is a signal for displaying a subtitle or a menu. 
 
     
     
       6. A display method comprising:
 performing electro-optical transfer function (EOTF) conversion for high dynamic range (HDR) on a video signal having a luminance range with luminance range of HDR to generate a video linear signal; 
 converting a first graphics signal having a luminance range with a maximum luminance 100 nit into a second graphics signal having a luminance range with a maximum luminance value that is decided in accordance with a maximum luminance that is displayable by a display; 
 performing the EOTF conversion for HDR on the second graphics signal to generate a graphics linear signal; 
 combining the video linear signal with the graphics linear signal to generate a composite signal; 
 converting a luminance range of the composite signal into a luminance range having a maximum value, the maximum value being larger than 100 nit and being the maximum luminance that is displayable by the display; and 
 displaying the composite signal with the luminance converted. 
 
     
     
       7. The display method according to  claim 6 , wherein
 converting the first graphics signal having a luminance range with the maximum luminance 100 nit into the second graphics signal having the luminance range with a maximum luminance value that is decided in proportion to the maximum luminance that is displayable by the display. 
 
     
     
       8. A display method comprising:
 performing electro-optical transfer function (EOTF) conversion for high dynamic range (HDR) on a video signal having a luminance range with luminance range of HDR to generate a video linear signal; 
 performing the EOTF conversion for HDR on a graphics signal having a luminance range with a maximum luminance 100 nit to generate a first graphics linear signal; 
 converting a first graphics linear signal into a second graphics linear signal having a luminance range with a maximum luminance value that is decided in accordance with a maximum luminance that is displayable by a display; 
 combining the video linear signal with the second graphics linear signal to generate a composite signal; 
 converting a luminance range of the composite signal into a luminance range having a maximum value, the maximum value being larger than 100 nit and being the maximum luminance that is displayable by the display; and 
 displaying the composite signal with the luminance converted. 
 
     
     
       9. The display method according to  claim 8 , wherein
 converting the first graphics linear signal into the second graphics linear signal having the luminance range with a maximum luminance value that is decided in proportion to the maximum luminance that is displayable by the display. 
 
     
     
       10. The display method according to  claim 6 , wherein
 the graphics signal is a signal for displaying a subtitle or a menu. 
 
     
     
       11. The display apparatus according to  claim 3 , wherein
 the graphics signal is a signal for displaying a subtitle or a menu. 
 
     
     
       12. The display method according to  claim 8 , wherein
 the graphics signal is a signal for displaying a subtitle or a menu.